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      18,000 BTU mini-split heat pump · Polar Series

      NOVAIR LEA20-MZ-LCT- 454-O

      Excellent cooling efficiency and average heating efficiency for a 18,000 BTU mini-split heat pump, and certified for cold climates.

      Ranks #8 of 465 18,000 BTU mini-splits for cooling efficiency, and costs about $477 a year to run in a mixed climate like Atlanta.

      SEER2
      27.0 Cooling efficiency over a season
      Excellent · beats 94%
      HSPF2
      10.0 Heating efficiency over a season
      Average · beats 43%
      EER2
      15.0 Cooling efficiency on a 95°F day
      Excellent · beats 91%
      Heat at 5°F
      19,800 BTU/h99% of its 47°F output
      Average · beats 48%

      A good fit if…

      • You want low cooling bills - its SEER2 beats 94% of mini-splits.
      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 19,800 BTU/h at 5°F.
      • You want steady temperatures and quiet running - the compressor varies its speed.

      Think twice if…

      • Nothing stands out - its ratings have no weak spot for its class.

      Calculate my running cost

      Details

      Specifications18,000 BTU, R-454B
      General
      BrandNOVAIR
      Outdoor unit modelLEA20-MZ-LCT- 454-O
      SeriesPolar Series
      TypeMini-split heat pump
      Nominal size18,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceApril 1, 2026
      Last certifiedSeptember 22, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better27.0 (range 27.0)
      EER2Efficiency at 95°F outdoors15.0
      Cooling capacity20,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better10.0
      Capacity at 47°F20,000 BTU/h
      Capacity at 17°F23,000 BTU/h
      Capacity at 5°F19,800 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater2.00
      ENERGY STAR cold climateYes
      Heating output as it gets colder99% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its best matchup at the standard test temperatures, in BTU/h:

      Certified matchups2 indoor units

      The same outdoor unit scores differently with each indoor unit. Ask your installer for the AHRI reference number of the exact system you are quoted.

      Indoor unitSEER2EER2HSPF2Heat @5°FAHRI ref.
      - novair · cold climate27.015.010.019,800218374491
      - novair · cold climate27.015.010.019,800218743566
      Yearly running cost in 10 large cities$352-$1,200

      At each state's average electricity price and the city's typical heating and cooling hours.

      Questions4
      What is the SEER2 rating of the NOVAIR LEA20-MZ-LCT- 454-O?
      The NOVAIR LEA20-MZ-LCT- 454-O is rated at up to 27.0 SEER2 and 15.0 EER2 for cooling and up to 10.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
      Is the NOVAIR LEA20-MZ-LCT- 454-O good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 19,800 BTU/h at 5°F with a COP of 2.00, so it is still 2.0 times as efficient as electric resistance heat at that temperature.
      How much does the NOVAIR LEA20-MZ-LCT- 454-O cost to run per year?
      At its rated efficiency it costs about $352-$1,200 a year in electricity in large U.S. cities, depending on climate and local rates - for example $470 in Phoenix and $1,030 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
      What refrigerant does the NOVAIR LEA20-MZ-LCT- 454-O use?
      It uses R-454B.

      Running cost and savings

      Pre-filled with this model. Pick your city and what you heat with today; everything else is optional.

      Heat pump $485/yrYou save $547/yrSee details ↓
      1. Where you live
      Adjust heating and cooling hours

      Filled in from your city's climate. Change them if you run the system much more or less than usual.

      2. The heat pump NOVAIR LEA20-MZ-LCT- 454-O
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $485
      Current system, per year
      $1,031
      You save per year
      $547
      Payback
      13.7 years
      Net after 10 years
      -$2,035

      Cooling $261Heating $224Electricity used: 3,030 kWhSaved vs. a minimum-efficiency heat pump: $306

      Estimates use the unit's rated SEER2 and HSPF2, full-load hours derived from NOAA 1991-2020 degree days, average residential electricity prices from the U.S. EIA (12 months to July 2026) and fuel prices from EIA (2025 for natural gas, week of 2026-10-05 for propane and heating oil). Very cold days that need backup heat are not modelled. Federal minimum for comparison: 14.3 SEER2 / 7.5 HSPF2.

      Similar 18,000 BTU models

      See all 465 18,000 BTU mini-splits, ranked

      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of September 22, 2026. How we use the data.